In certain situations a participant who has logged in to Perception to take an assessment may encounter the following error:

Access denied. Unable to proceed due to improper call of Perception

A possible cause for this is illegal characters appearing in the details fields for the participant. However, this may not be the only cause. It is recommended that you follow the instructions included in the Knowledge Base article and if this does not resolve your issues you contact Questionmark Technical Support.

The error is recorded in the Perception event logs (perception.log) with a similar entry to the following:

The cause of this error is due to the use of illegal characters in the Detail fields for this participant. Detail fields work by storing participant specific information in Special Fields in the repository. For example, the diagram below represents some information that can be stored in Detail fields which are then stored in the repository.

It is possible to assign what Detail information to store in specific Special Field entries in the database. These can be assigned in the Server Settings page in Enterprise Manager or the perceptionv4.ini file.

The additional participant information is commonly added to the Details tab for participants, this is shown below.

To resolve this issue remove any illegal characters from the Details entries. Data stored in the Details fields should only include characters A - Z and 0 - 9. Examples of illegal characters that should not be included are:

• &
• _
• %
• #

Once any illegal characters have been removed the participant information can be saved. The participant should then be able to access the assessment without an error being produced.

Finding more information

For further information about using the Details fields and Special Fields to record participant demographics, please refer to the following Knowledge Base articles:

• How can I arrange for demographic data to be copied from the security tables to the answer tables in the Perception database when using perception.dll?
• How can I give participants the option of viewing and amending their own demographic data?

If you have ensured that no illegal characters have been included in the Detail fields but are still receiving the same error, please contact Technical Support for further information.